Second-order corrections to slow-roll inflation in the brane cosmology

TL;DR

This paper computes second-order corrections to the power spectrum and spectral indices in brane inflation, revealing small differences from standard inflation that are unlikely to be observationally distinguishable.

Contribution

It provides detailed calculations of second-order effects in brane inflation, extending previous first-order analyses and comparing them with standard inflation results.

Findings

Power spectrum is enhanced in brane inflation.

Spectral index is suppressed compared to standard inflation.

Second-order corrections are small and not distinguishable observationally.

Abstract

We calculate the power spectrum, spectral index, and running spectral index for the RS-II brane inflation in the high-energy regime using the slow-roll expansion. There exist several modifications. As an example, we take the power-law inflation by choosing an inverse power-law potential. When comparing these with those arisen in the standard inflation, we find that the power spectrum is enhanced and the spectral index is suppressed, while the running spectral index becomes zero as in the standard inflation. However, since second-order corrections are rather small, these could not play a role of distinguishing between standard and brane inflations.